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Home My WebLink About20060706IPC to Staff 19-24, 28, 47, 72.pdfiSiI IDAHO POWER COMPANY O. BOX 70 BOISE, IDAHO 83707 July 6, 2006 ~~b" t; QUNE Senior Attorney 2006 JUL -6 PH 3: 32 IDAHO PUBLIC UTiliTIES COMMISSION An IDACORP Company Jean D. Jewell, Secretary Idaho Public Utilities Commission 472 West Washington Street P. O. Box 83720 Boise , Idaho 83720-0074 Re:Case No. IPC-06- Idaho Power Company s Response to the First Production Request of Commission Staff Dear Ms. Jewell: Please find enclosed for filing an original and two (2) copies of Idaho Power Company s Response to the First Production Request of Commission Staff regarding the above-described case. I would appreciate it if you would return a stamped copy of this transmittal letter to me in the enclosed self-addressed stamped envelope. Very truly yours C~idJcL-Barton L. Kline BLK:sh Enclosures Telephone (208) 388-2682 Fax (208) 388-6936, E-mail BKline(g)idahopower.com ic' BARTON L. KLINE ISB #1526 MONICA B. MOEN ISB #5734 Idaho Power Company O. Box 70 Boise, Idaho 83707 Telephone: (208) 388-2682 FAX Telephone: (208) 388-6936 REceIVED 2006 JUl-6 PM 3: 32 IDAHO PU8L1CUTILITIES COMMISSION Attorney for Idaho Power Company Street Address for Express Mail 1221 West Idaho Street Boise , Idaho 83702 BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION IN THE MATTER OF THE APPLICATION OF IDAHO POWER COMPANY FOR A CERTIFICATE OF PUBLIC CONVENIENCE) AND NECESSITY FOR THE RATE BASING OF THE EV ANDER ANDREWS POWERPLANT. CASE NO. IPC-06- IDAHO POWER COMPANY' RESPONSE TO THE FIRST PRODUCTION REQUEST OF COMMISSION STAFF COMES NOW, Idaho Power Company ("Idaho Power" or "the Company and in response to the First Production Request of the Commission Staff to Idaho Power Company dated June 16, 2006, herewith submits the following information: IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page REQUEST NO. 19: Please describe any transmission system additions or improvements , including cost , which will be needed to interconnect the Evander Andrews plant into Idaho Power s existing system. RESPONSE TO REQUEST NO. 19: $ 4.6 Million - Bennett Mountain to Evander Andrews 230 kV line and substation terminals $17.8 Million - Evander Andrews to Mora 230 kV line and substation improvements $ 0.4 Million - 230 kV generator connection terminal at Evander Andrews Substation The response to this request was prepared by Roger Grim , Engineer System Planning, Idaho Power Company, in consultation with Barton L. Kline , Senior Attorney, Idaho Power Company. IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page 2 REQUEST NO. 20: Please describe any permits that will be required for transmission system additions or improvements and provide time estimates of when such permits could be obtained. If any permits will be required , what is their status? RESPONSE TO REQUEST NO. 20: The following activities are required prior to receiving right of way(ROW) permission to cross BLM land. Environmental Assessment - currently being written Candidate Conservation Agreement (may be required) - currently being assessed/writte n Biological Assessment (may be required) - currently being assessed/written State Historic Preservation Office (SHPO) - cultural resource survey performed in 2005. Small addition to route done in 2006. Consultation with SHPO following completion of technical report. A Conditional Use permit must be issued from Ada County. A Conditional Use permit may be required from Elmore County (none was required for the Bennett Mountain to Rattlesnake line). Idaho Power will check with Bureau of Reclamation to see if they will accept documents prepared for the BLM for their ROW process. Idaho Power will check with State Lands to see if they need additional information for ROW. None of these requirements are presently anticipated to delay the completion of the transmission improvements. The response to this request was prepared by Roger Grim , Engineer System Planning, Idaho Power Company, in consultation with Barton L. Kline , Senior Attorney, Idaho Power Company. IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page 3 REQUEST NO. 21: Please describe any transmission system additions or improvements, including cost and construction timing, which will be needed between Mountain Home and Boise in order to accommodate the Evander Andrews Plant. Are there any improvements being made in the general vicinity of the Evander Andrews plant that Idaho Power would have made whether the Evander Andrews plant was built or not? RESPONSE TO REQUEST NO. 21: $ 4.6 Million - In-service Winter 2007 - Bennett Mountain to Evander Andrews 230 kV line and substation terminals $17.8 Million - In-service Spring 2008 - Evander Andrews to Mora 230 kV line and substation improvements $ 0.4 Million - In-service Winter 2007 - 230 kV generator connection terminal at Evander Andrews Substation Operational concerns presently exist between the Mountain Home area and Boise. While no commitment had been made for transmission system improvements to address the operational concerns prior to this generator interconnection process, Idaho Power now intends to make two additional transmission improvements in the same timeframe as the transmission improvements needed to interconnect Evander Andrews generation. These are: (1) a 230/138 kV transformer at Evander Andrews and (2) the re-conductor of the Evander Andrews/Mountain Home Junction 138 kv transmission line. These improvements are proposed to alleviate the above-referenced operational concerns. These transmission improvements are estimated to cost approximately $4 million. The combination of the $22.8 million to IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page 4 interconnect the generator and the additional $4 million to address existing operational concerns , compliment each other and accomplish both objectives. The response to this request was prepared by Roger Grim, Engineer System Planning, Idaho Power Company, in consultation with Barton L. Kline , Senior Attorney, Idaho Power Company. IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page 5 REQUEST NO. 22: Please describe the transmission constraints that made it desirable or necessary for Idaho Power to specify in the March 2005 RFP that Idaho Power is interested in proposals that can provide electric capacity to the Treasure Valley load center. Provide copies of any analysis or transmission system studies in which these constraints were identified-and described. RESPONSE TO REQUEST NO. 22: The following transmission constraints are either fully subscribed or lack sufficient unsubscribed transmission capacity to accommodate the March 2005 RFP: Idaho to Northwest . Idaho-Montana Bridger West . Idaho-Sierra Path C Construction of new transmission facilities would be required to increase the capacity of any of the above constraints. Construction lead times for new transmission lines on new rights of way, make it impractical to meet the in-service dates called for in the RFP. A discussion and descriptions of Idaho Power s transmission constraints are contained on pages 18-22 of the 2004 IRP. The 2004 IRP is available at the following link: http://www. idahopower.com/pdfs/enerqycenter/irp/2004/2004 I RP final. pdf Additional information and analysis is contained in the attached "FERC FORM No. 715 PART VI" document. The electronic version of this document has the following file name: "Perform6.doc IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page 6 The response to this request was prepared by Roger Grim, Engineer System Planning, Idaho Power Company, in consultation with Barton L. Kline, Senior Attorney, Idaho Power Company. IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page 7 REQUEST NO. 23: Please provide cost estimates and a description of the improvements that would be necessary for Idaho Power to relieve transmission constraints into its system such that power could be imported from the market as an alternative to building the Evander Andrews plant. Provide a copy of any studies or analysis that has been completed. RESPONSE TO REQUEST NO. 23: The attached "FERC FORM No. 715 PART VI" document contains cost estimates and descriptions of improvements. The electronic version of this document has the following file name: "Perform6.doc The response to this request was prepared by Roger Grim , Engineer System Planning, Idaho Power Company, in consultation with Barton L. Kline , Senior Attorney, Idaho Power Company. IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page 8 REQUEST NO. 24: Please describe in detail any transmission system improvements , upgrades or additions that have recently been made or are planned in the general vicinity of the proposed Evander Andrews plant that are not contingent upon or considered a part of the Evander Andrews Plant. Provide a copy of any study or analysis completed that recommended such improvements , additions or upgrades. For any upgrades that have recently been completed , please provide records showing the total costs for the improvements, additions or upgrades. RESPONSE TO REQUEST NO. 24: No recent transmission system improvements, upgrades or additions have been made in the general vicinity of the Evander Andrews plant. Two new transmission system improvements are planned in conjunction with the improvements required to interconnect the generator. The improvements are a 230/138 kV transformer Evander Andrews and the re-conductor of the Evander Andrews-Mountain Home Junction 138 kv line. These improvements will address pre-existing operational concerns and as a result will not have their associated costs allocated to the generator interconnection. These improvements are discussed in the attached Feasibility Study Report for the proposed Evander Andrews Peaker. The response to this request was prepared by Roger Grim, Engineer System Planning, Idaho Power Company, in consultation with Barton L. Kline , Senior Attorney, Idaho Power Company. IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page 9 REQUEST NO. 28: Please provide a copy of all studies or estimates used to develop the upper limit estimate of $22.8 million to interconnect the project to the Company s transmission system. Has the study (referred to on page 5 of the Application) been completed to define the cost of constructing transmission and substation facilities required to interconnect the project with the Company transmission system? If so, please provide a copy of the study. If the study has not yet been completed , when is completion expected? RESPONSE TO REQUEST NO. 28: The large generator interconnection study process is segmented into three studies. The first study in the process is the "Feasibility Study . As the name implies this study focuses on the question , " Is it feasible to interconnect the generator?". During this study, reasonable interconnection alternatives are evaluated using powerflow analysis and those interconnection alternatives which provide acceptable performance have high level cost estimates developed. The Feasibility Study for a third unit at the Evander Andrews location was completed in August of 2005 and is attached. The initial high level cost estimates in the feasibility study totaled $21.8 million for interconnecting the third unit at Evander Andrews. Subsequent review determined an additional million of communications equipment would be required. The next phase of studies is referred to as the "System Impact Study During the system impact study, transient stability analysis and detailed short circuit analysis is performed to further assess the performance of the proposed interconnection alternative. The System Impact Study for the Evander Andrews project is currently underway. IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page 10 The third phase of studies is referred to as the "Facility Study . The facility study starts the detailed design phase of the project and includes detailed construction estimates. The facility phase of the project can begin after competion of the system impact study and upon receiving authorization from the customer. The response to this request was prepared by Roger Grim , Engineer System Planning, Idaho Power Company, in consultation with Barton L. Kline, Senior Attorney, Idaho Power Company. IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page 11 REQUEST NO. 47: Please explain why the estimated transmission costs for the Evander Andrews plant are expected to be approximately double the transmission costs for the Bennett Mountain project when the locations of the two plants are only a few miles apart. RESPONSE TO REQUEST NO. 47: Prior to the addition of the Bennett Mountain project , the Midpoint West transmission constraint had sufficient uncommitted transmission capacity to transmit the output of the Bennett Mountain plant to Boise. The transmission improvements required to interconnect the Bennett Mountain plant to the transmission grid , were essentially a 230 kV line from the plant location to the closest existing bundled 230 kV line(approx. 4 miles) and a substation to interconnect the transmission lines. Prior to the addition of the third unit at Evander Andrews , insufficient uncommitted Midpoint West transmission capacity remained to transmit the output of the third unit at Evander Andrews to Boise. As a result, a new transmission line was required from the Mountain Home area to Boise, to provide the additional transmission capacity required to interconnect the third unit at Evander Andrews. The response to this request was prepared by Roger Grim , Engineer System Planning, Idaho Power Company, in consultation with Barton L. Kline, Senior Attorney, Idaho Power Company. IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page 12 REQUEST NO. 72: Please elaborate on the highlighted portion of the following statement from page 17, lines 2-6 of Said's direct testimony: "Although the transmission system will require additional investment in order to integrate the Project those improvements will provide capacity during all seasons and improve reliability of the Company s transmission system." Quantify, if possible, seasonal increases in transmission capacity and improvements in reliability. RESPONSE TO REQUEST NO. 72: The third unit at Evander Andrews is expected to run , for the most part during the summer and winter peak periods of low-hydro years. The additional transmission capacity associated with the required transmission improvements will exist during all hours of all seasons. During those hours that the third unit at Evander Andrews is not running, the additional transmission capacity is available for other uses and their associated benefits. Presently there are three 230 kV transmission lines making up the Midpoint West transmission system and they all terminate in the vicinity of Boise Bench substation. The addition of the transmission improvements associated with the Evander Andrews project will create a fourth 230 kV transmission line from the Mountain Home area to the Boise area. The addition of a fourth 230 kV line will increase the redundancy and resulting reliability of the transmission system. Further reliability improvements are gained by terminating the new line at Mora Substation; a remote location other than Boise Bench. IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page 13 The response to this request was prepared by Roger Grim, Engineer System Planning, Idaho Power Company, in consultation with Barton L. Kline , Senior Attorney, Idaho Power Company. +tA. DATED at Boise, Idaho, this (0 -day of July 2006. ~utJ BART N L. KLINE Attorney for Idaho Power Company --- IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION REQUEST OF COMMISSION STAFF Page 14 CERTIFICATE OF SERVICE I HEREBY CERTIFY that on this day of July, 2006, I served a true and correct copy of the within and foregoing IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF COMMISSION STAFF upon the following named parties by the method indicated below, and addressed to the following: Commission Staff Hand Delivered Donovan Walker US. Mail Deputy Attorney General Overnight Mail Idaho Public Utilities Commission FAX 472 W. Washington (83702)Email: Donovan.walker(g)puc.idaho.gov O. Box 83720 Boise, Idaho 83720-0074 Industrial Customers of Idaho Power Hand Delivered Peter 1. Richardson, Esq.US. Mail Richardson & O'Leary Overnight Mail 515 N. 27th Street FAX O. Box 7218 Email: peter(g)richardsonandoleary.com Boise, Idaho 83702 Don Reading Ben Johnson Associates Hand Delivered 6070 Hill Road US. Mail Boise, Idaho 83702 Overnight Mail FAX Email: dreading(g)mindspring.com Mountain View Power, Inc.Hand Delivered Ronald L. Williams US. Mail Williams Bradbury, P.Overnight Mail O. Box 2128 FAX Boise, Idaho 83701 Email: ron (g)williamsbradbury.com Robert D. Looper, President Hand Delivered Mountain View Power, Inc.US. Mail 1015 W. Hays Street Overnight Mail Boise, Idaho 83702 FAX Email: rlooper(g)spellc.com ~~- Barton . KlIne CERTIFICATE OF SERVICE , Page IDAHO POWER COMPANY CASE NO. IPC-O6- FIRST PRODUCTION REQUEST OF COMMISSION STAFF RES PO N S E REQUEST NO. 22 IDAHO POWER COMPANY FERC FORM No. 715 PART VI PERFORMANCE EV ALUA TION Enclosed Idaho Power Company s statement regarding performance evaluation is enclosed. Idaho Power Company s performance evaluation statement plus the WECC 2006 Path Rating Catalog and other documents submitted by WECC constitute Idaho Power Company s complete response to FERC for Part VI. Contact Person: Mailing Address: Mark D. Hanson O. Box 70 Boise, Idaho 83707-0070 mhanson (g)idahopower.com 208-388-2253 208-388-6647 E- mail Telephone Number: Facsimile Number: FERC Form No. 715 2006 Filing Part VI: Performance Evaluation Evaluation of Transmission System Performance The WECC Path Rating Catalog identifies existing transmission path constraints in the Idaho Power System. The Catalog specifies known limits as well as the conditions when the limits occur. In addition, existing perfonnance is described and stability limitations are identified. The need to increase transmission transfer capacity in the future will be driven by the need to integrate new generation resources, new requests for finn transmission capacity, or intemalload growth. The following paragraphs discuss opportunities to increase transfer capacity for specific transmission paths. This reflects the most current planning and is subject to change as new infonnation becomes available. Other documents that may be helpful in studying future developments include the Department of Energy s Fonn EIA-411 and WECC's Ten-Year Coordinated Plan Summary 2005-2015. Idaho to Northwest The limits of the Idaho to Northwest transmission path are described in the Path Rating Catalog (see Path #14). The present interconnection between Idaho Power and the Northwest consists of one 500 kV , three 230 kV, and one 115 kV lines. East to West: The simultaneous east to west transfer capacity is 2400 MW. West to East: The present simultaneous west to east transfer capacity from the Northwest is 1200 MW. However, operating restrictions on the Brownlee East and Oxbow North paths (see corresponding sections for discussion) may prevent full utilization of this capacity. Restrictions are reached during simultaneous Hells Canyon Complex generation with imports from the Northwest. Brownlee East The Brownlee East transfer path is described in the Path Rating Catalog (see Path #55) and has an accepted rating of 1850 MW. Oxbow North This transfer path is comprised of the Brownlee-Hells Canyon 230 kV and Oxbow-Lolo 230 kV lines (flows are metered at Hells Canyon and Imnaha). The Oxbow North simultaneous nomogram limit is defined by the emergency thennal capacity of either the Brownlee-Hells Canyon or Oxbow-Lolo 230 kV transmission line, following the loss of the other 230 kV line. Limits are reached during simultaneous heavy Hells Canyon Complex generation and heavy import conditions which typically occur during the spring and early summer with above average hydro conditions in the Northwest. This path does not restrict east to west transfers from Idaho to the Northwest. FERC Form No. 715 2006 Filing Part VI: Performance Evaluation The study conditions used to determine the Oxbow North transfer capacity were high Northwest to Idaho transfers on the Oxbow-Lolo and Hells Canyon-Walla Walla 230 kV lines simultaneous with high generation at the Hells Canyon plant. Remedial actions are required for the loss of the Brownlee-Hells Canyon 230 kV line during high flow conditions North of Oxbow. Generator unit tripping is required at Hells Canyon under these conditions to maintain dynamic stability of the remaining Hells Canyon units. Simultaneous loss of the Brownlee-Hells Canyon and the Oxbow-Lolo 230 kV circuits limits the ability to fully utiltize the 1200 MW import capability under high Hells Canyon Complex generation. Additional facilities including new/uprated lines (a new 230 kV circuit from the Hells Canyon/Imnaha area and increasing the thermal rating of the existing Hells Canyon-Brownlee 230 kV line) and additional flow control measures (a phase shifter) will be required to fully resolve this limitation. Long Term ATC across the Northwest-Idaho and Brownlee East cutplanes is fully subscribed West-to-East. Idaho Power has considered six conceptual West-to-Eeast upgrades in the past to the Northwest-Idaho and Brownlee East cutplanes. These are: Project Voltage Capacity Cost West-East (in 2000 $) McNary-Brownlee 230 k V 100 MW $122 000 000 NW- Lower Monumental-Brownlee 500 kV 100 MW $227 000,000 NW- McN ary- Brownlee-Boise Bench-Midpoint 345 kV 475 MW $307 000 000 NW-ID/BE Lower Monumental-Melba 500 kV 575 MW $361 000 000 NW-ID/BE Lower Monumental- Melba-Midpoint 500 kV 600 MW $483 000 000 NW - ID/BE Lower Monumental-Melba-Midpoint-Borah 500 kV 600 MW $501 000 000 NW -ID/BE Idaho-Sierra The constraints for this transmission path are the Sierra import and export limits as explained in the Path Rating Catalog (see Path #16). With the completion of the Alturas project between Sierra and the Northwest and the Falcon-Gonder 345 kV project internal to Sierra s system, there is now more opportunity to fully utilize the transfer capabilities on the Idaho-Sierra path. FERC Form No. 715 2006 Filing Part VI: Performance Evaluation Borah West The West of Borah transfer path is specified in the Path Rating Catalog (see Path #17) and has an existing East to West rating of 2307 MW. To accommodate additional transmission requests, the Borah West transfer capacity is being increased. The Borah West up rate project, which is currently underway, will increase the Borah West transmission capacity an additional 250 MW from 2307 MW to 2557 MW and has a proposed in-service date of May 2007. The major component of this project is to rebuild the American Falls-Adelaide and Adelaide-Hunt 138 kV lines to 230 kV. The Borah West up rate project facilities for the plan of service for an additional 250 MW increase in transfer capacity are listed below: Brady-Am Falls 138 kV line, Re-conductor 0.4 mile, single 1272 kcmil ACSR Borah-Hunt 230 kV line, Rebuild 70.0 miles of 138 kV to 230 kV , single 1590 kcmil ACSR Borah 345 kV, 175 Mvar Shunt Capacitor Midpoint 345 kV, 175 Mvar Shunt Capacitor The Borah West up rate project has completed the WECC three phase path rating process and was granted Phase III status in March of 2003. Idaho - Montana The transfer capacity for the Idaho - Montana path is specified in the Path Rating Catalog (see Path #18). The thermal capacity of the Anaconda-Antelope 230kV line is 462MW; however, the transfer capacity of this line is steady-state voltage limited to 250MW. Idaho Power has considered three conceptual upgrades in the past to the Idaho-Montana cutplanes. These are: Project Voltage Capacity Cost North-South (in 2000 $) Mill Creek-Antelope 161 kV 100 MW $105 000 000 Garrison-Mill Creek-Antelope-Brady 230 kV 250 MW $150 000 000 Garrison- Borah- Midpoint 500 kV 800 MW $347 000 000 Brid2er West The Bridger West transfer path is specified in the Path Rating Catalog (see Path #19) and has an existing East to West rating of 2200 MW. To increase the Bridger West transfer capacity beyond 2200 MW to approximately 2400 MW will require the replacement of the Borah and Kinport series capacitor banks, and additional shunt reactive support to be added in the Bridger system. FERC Form No. 715 2006 Filing Part VI: Performance Evaluation Midpoint West The Midpoint West transfer path is comprised of the Midpoint-Dram 230kV line, the Midpoint-Rattlesnake #2230 kV line, the Midpoint-Boise Bench #3 230kV line, and the Upper Salmon - Mt Home Jet and the Lower Malad - Mt Home Jet 138 kV lines. The east to west transfer limit is approximately 11O0MW at the Midpoint end. The west to east transfer limit is approximately 750MW and is based on the N-l rating of the three 230kV lines and the underlying 138 kV transmission system. Under west to east flow conditions, the transfer limit was developed with high Northwest to Idaho transfers resulting from above average hydro conditions, high Hells Canyon Complex generation and low eastern thennal resources. With uprating of the Boise Bench-Dram 230 kV line, the west to east transfer limit of Midpoint West can be increased approximately 150MW. Future Facility Additions Idaho Power considered the Southwest Intertie Project (SWIP) to capture the economics regional diversity more fully, thus making the best use of existing resources and potentially deferring new generation projects. Idaho Power is no longer pursuing this project and has granted an option for it to Great Basin Transmission, LLC to develop this transmission corridor. SWIP can offer significant benefit to the Northwest and Southwest utilities by enhancing competition and efficiency in the regional bulk power market. The project is described below. Southwest Intertie Project: The SWIP is a proposed 500kV transmission system from Midpoint substation to Crystal substation, a Nevada Power Company s (NPC) substation located north of Las Vegas, NY. The proposed bi-directional rating of the line is approximately 1200MW. SWIP will be approximately 520 miles long and will require one or two series capacitor stations in addition to tenninations in the Midpoint and Crystal substations. At Midpoint, SWIP will require a 500/345kV transfonnation only if the Borah-Midpoint 345 to 500kV upgrade project is not built. In addition, to fully develop and utilize the SWIP project, additional transmission projects will be required to increase the W -E and E- W Idaho to Northwest transfer capacity. The SWIP integration with the southern Nevada transmission system is planned to be at NPC's Crystal substation. ID AH POWER CO MP ANY CASE NO. IPC-O6- FIRST PRODUCTION REQUEST OF COMMISSION STAFF RESPONSE TO REQUEST NO. 23 See documents attached to Response to Request No. 22 IDAHO POWER COMPANY CASE NO. IPC-O6- FIRST PRODUCTION REQUEST OF COMMISSION STAFF RESPONSE TO REQUEST NO. 24 LARGE GENERA TOR INTERCONNECTION FEASIBILITY STUDY REPORT for the 230 KV INTERCONNECTION OPTION EV ANDER ANDREWS PROJECT for Idaho Power Power Marketing, Interconnection Customer for connection of A 200 MW SIMPLE CYCLE GAS TURBINE PEAKING PROJECT EV ANDER ANDREWS PROJECT IDAHO POWER COMPANY, Transmission Provider TRANSMISSION SYSTEM FINAL REPORT August 4, 2005 1.0 Introduction Idaho Power Power Marketing has contracted with Idaho Power Company (IPC) to perform a Large Generator Interconnection Feasibility Study for Network Resource Interconnection Service at 230 kV for the integration of a new 200 MW simple cycle gas turbine peaking project. The proposed location is the Evander Andrews Project near Mountain Home, Idaho. This report documents the basis for and the results of this Feasibility Study. It describes the proposed interconnection alternatives, the study cases used, outage scenarios assumed and results of all work in the areas of concern. Summary The performance of three interconnection alternatives was evaluated to integrate a 200 MW simple cycle gas turbine, located at Evander Andrews Project, into the Idaho Power System. Alternative #3 is the recommended alternative. Alternative #1: Alternative #2: Alternati ve #3: Construct a radial 230 kV interconnection line, from a new 230 kV substation at Evander Andrews, to the Midpoint-Boise Bench #3 transmission line. Numerous N-1 contingencies resulted in unacceptable overloads for this alternative. The additional improvement of a 230/138 kV transformer at Evander Andrews was evaluated in an unsuccessful attempt to achieve acceptable performance under N-1 outage conditions. Construct two new 230 kV transmission lines from Bennett Mountain to Evander Andrews and Evander Andrews to Rattlesnake. These lines would complete a 230 kV loop from Rattlesnake to Bennett Mountain to Evander Andrews and back to Rattlesnake. In addition, the Dram-Midpoint #1 230 kV line would be looped into Rattlesnake and rebuilt to support bundled 230 kV conductors west of Rattlesnake. Additional transmission modifications were also modeled at DRAM substation to make the "Old Midpoint to DRAM #1" 230 kV line bypass the DRAM Substation and terminate at Boise Bench. A 230/138 kV transformer was modeled at Evander Andrews to improve system performance under N-1 conditions. Alternative #2 has one N-1 outage that produces an overload that exceeds 115% of continuous rating. In addition three N-1 contingencies still require curtailments for Alternative #2. Alternative #2 is an unacceptable alternative due to the N-1 outage that produces an overload that exceeds 115%. Alternative #2 is anticipated to be similar in cost to Alternative #3, yet does not perform as well. Rebuild a de-energized 132 kV transmission line to 230 kV construction between Bennett Mountain and Mora Substations. This alternative utilizes the 406 line route which passes in the vicinity of Evander Andrews. The west end of the 230 kV line is assumed to terminate at a new 230 kV Mora Substation which is folded into the Boise Bench-Caldwell 230 kV line. No 230/138 kV transformer is modeled to tie the two Mora busses. A 230/138 kV transformer was modeled at Evander Andrews to improve system performance under N- conditions. Studies revealed the need to reconductor/rebuild the Evander Andrews to Mountain Home Junction 138 kV line. With the previously mentioned additions in-service, two N-l outages produce overloads above equipment continuous ratings. One overload only requires a 2% reduction in loading to fall to a level that can be sustained continuously. Opening another lightly loaded line can mitigate the other overload. The estimated total cost for this alternative is approximately $26 Million, with approximately $22 Million allocated Idaho Power Power Marketing for the generator interconnection improvements and the remaining $4 Million allocated to Idaho Power Delivery to correct existing operational concerns. Following the execution of either a Large Generator Interconnection Agreement or a Engineering & Procurement Agreement by Idaho Power Power Marketing, Idaho Power Company estimates the time required to construct these facilities is approximately 18-21 months. These cost estimates include direct equipment and installation labor costs, indirect labor costs and overheads, and allowance for funds used during construction (AFUDC). A cursory attempt has been made in this study to characterize each transmission improvement as either needed to integrate the proposed generator" or "needed to correct existing operational concerns . The proposed cost allocation is subject to change, as more information is known. These are cost estimates only and final charges to the customer will be based on the actual construction costs incurred. Summary of Interconnection Request A request was made to Idaho Power Co. by Idaho Power Power Marketing to study the interconnection of a proposed 200 MW simple cycle gas turbine at the Evander Andrews Project, near Mountain Home, Idaho, to Idaho Power s transmission system at the 230 kV level for Network Resource Interconnection Service. Scope of Interconnection Feasibility Study The Interconnection Feasibility Study was done and prepared in accordance with the FERC Order 2003-, Standard Large Generator Interconnection Procedures, to provide a preliminary evaluation of the feasibility of the interconnection of the proposed large generating project to the Idaho Power transmission system. This study will only be concerned with the capabilities of the Idaho Power system to manage this new resource within the study area of the proposed interconnection. Description of Proposed Generating Project Idaho Power Power Marketing proposes to connect a 200 MW simple cycle gas turbine to the Idaho Power 230 kV transmission system, at the existing Evander Andrews Power Complex 1862 NW Mashburn RD., Mountain Home, ill 83647. The maximum generating capacity of the proposed unit is estimated to be 200 MW for both summer and winter temperatures. The equipment is described as being, a Siemens Westinghouse 501F Econopac. The proposed commercial operation date is April 1 , 2007. Description of Existing Transmission Facilities At the Scoping Meeting for this Interconnection Request, it was agreed that the interconnection voltage to be studied would be 230 kV. The existing generating units at Evander Andrews Power Complex utilize the 138 kV transmission grid. No 230 kV transmission is present at Evander Andrews at this time. Evander Andrews has four 230 kV lines in relatively close proximity. Three of them run from the Midpoint Substation(north of Twin Falls, ill) to the east Boise area. The closest is the Midpoint- DRAM #1 line, which is approximately 4 miles Northeast of Evander Andrews. This line utilizes single 715.5 MCM conductors and has a continuous rating of 339 MV A. The Rattlesnake-Boise Bench #2 line is approximately 5 miles Northeast of Evander Andrews and utilizes a 2 conductor bundle of 715.5 MCM. This line has a continuous rating of 677 MV A. The Midpoint-Boise Bench #3 line is approximately 7 miles Northeast of Evander Andrews. This line has similar conductors and the same rating as the Rattlesnake-Boise Bench #2 line. The fourth 230 kV line in the area is the Rattlesnake-Bennett Mountain line. It is approximately 5 miles to the Southeast of Evander Andrews. This line utilizes single 1272 MCM conductors and has a continuous rating of 478 MV A. In addition to the three Midpoint to the east Boise area 230 kV lines previously mentioned, there are two 138 kV circuits which can carry power from the Mountain Home area to the Boise Area. They are: Mountain Home Junction-Lucky Peak-Micron 138 kV Line Mountain Home Junction-Evander Andrews-Strike-Swan Falls-Bowmont 138 kV Line Generators located in the Mountain Home area which are intended to serve load growth in the Treasure Valley area, will be adding new incremental flows on top of existing committed east-to- west transactions across the Midpoint West transmission cutplane. This feasibility study will model 1100 MW of transfers across the Midpoint West cutplane , prior to this proposed generator addition. For these studies, the flow level of the Midpoint west cutplane is defined as the sum of the flows on the following lines: . Midpoint-DRAM #1 230 kV line . Midpoint-Rattlesnake #2230 kV Line . Midpoint-Boise Bench #3230 kV Line Lower Malad-Mountain Home Junction 138 kV Line Upper Salmon-Mountain Home Junction 138 kV Line Description of Configurations Studied Since the most limiting operating conditions are expected during heavy production on the upper and middle Snake and Boise River hydro plants, with heavy east-west transfers across the Idaho Power transmission system, the injection of the simple cycle gas turbine s 200 MW output was inserted into a power flow case that would simulate committed (1100 MW) pre- contingency flows on the Midpoint West transmission path. In accordance with the Scoping Meeting for this Feasibility Study Request, three alternatives were studied, all of which employed a 230 kV interconnection voltage. Alternative #1 employed a radial 230 kV line to connect the generator to the Midpoint-Boise Bench #3 transmission line. The line was modeled as being 7.7 miles in length and utilized 1272 MCM single conductor construction. An additional improvement of a 230/138 kV 200 MV A transfonner(duplicate of the Midpoint unit) was explored at Evander Andrews to improve the perfonnance of this alternative. Alternative #2 calls for the construction of two new 230 kV transmission lines from Bennett Mountain to Evander Andrews, and Evander Andrews to Rattlesnake. These lines would complete a 1272 MCM single conductor 230 kV loop from Rattlesnake to Bennett Mountain to Evander Andrews and back to Rattlesnake. In addition, the Dram-Midpoint #1 230 kV line would be looped into Rattlesnake and rebuilt to support a two conductor bundle of 715.5 MCM conductors west of Rattlesnake. Additional transmission modifications were also modeled outside of DRAM substation to make the "Old Midpoint to DRAM #1" 230 kV line bypass the DRAM Substation and tenninate at Boise Bench. The combination of bundled conductors and folding the #1 line into Rattlesnake Substation necessitated the change to avoid overloads at DRAM associated with the loss of the DRAM to Boise Bench 230 kV line. A 230/138 kV 200 MV A transfonner(duplicate of the Midpoint unit) was modeled at Evander Andrews to improve system perfonnance under N-l conditions. Alternative #3 employed the rebuild of a de-energized 132 kV transmission line to 230 kV bundled 795 MCM construction between Bennett Mountain and Mora Substations. This alternative utilizes the 406 line route (originally was the Upper Salmon to Caldwell line) which passes in the vicinity of Evander Andrews. The west end of this new 230 kV line is assumed to tenninate at a new 230 kV Mora Substation , which is folded into the Boise Bench-Caldwell 230 kV line. No 230/138 kV transfonner is modeled to tie the two Mora busses. A 230/138 kV 200 MV A transfonner(duplicate of the Midpoint unit) was modeled at Evander Andrews to improve system perfonnance under N-l conditions. Studies also revealed the need to reconductor/rebuild the Evander Andrews to Mountain Home Junction 138 kV line , with this alternative. Post-transient Study Results This Interconnection Feasibility Study Report is for Network Resource Interconnection Service at 230 kV , for a 200 MW simple cycle gas turbine at the Evander Andrews Power Project. System transfers across the Midpoint West cutplane are modeled at 1100 MW prior to the proposed transmission improvements or the proposed generator producing any power. Hydro generation production for the Boise & Snake plants , were modeled at heavy, but realistic levels. Ouput levels for the existing peakers at Evander Andrews and Bennett Mountain were varied over their operating ranges as appropriate. N-O and N-l outage perfonnance for the existing system are recorded. As agreed in the Scoping Meeting, three alternatives were evaluated. For each alternative, the new generator s output was taken to its maximum level of 200 MW and system conditions recorded for both N-O and N-l outages. Existing System The following one line diagram depicts the existing system with no outages. Mid oint West = 1100 MW u..""";~.: w' ~~'~',~ \:':;,""" ""'""'" """,""'" fA-.i~~5::r-;C . """"'L ~"" ~~1~.~1~. Existing System - No Outages Figure 1 For the existing system, seven N-l outages produce overloads that exceed the continuous rating of elements of the transmission system. The N-s that produce overloads with the existing system are included in Appendix B , Figures 9 - 15. Alternati ve # 1 The following one line diagram depicts the system with Alternative #1 added, full output of the generator, and with no outages. BOWMONT1.01," ----~" SWANFALL S1lUKE ,%" "", 1,02," 1.03,"I;W ~~'"",' ' il'::SWNFl PO r'~ """ 1.02," , "1SWANFALL. 1.00," 9.0MW(i!:iJ/ O.B Mm \.' 90MWBM", Mid oint West = 1063 MW ::;;g~:-:., "iIt, BURNS , ." /, I.O"" Alternative #1 - No Outages Figure 2 Alternative #1 has multiple N-l outages that produce overloads that exceed 115% of continuous ratings. Some of the resulting overloads are reduced with the addition of the Evander Andrews 230/138 kV trans fonner, and others are increased. The largest overloads are produced by the Lockman Butte to Boise Bench #3230 kV line outage. The following one line depicts a 128 % loading on the Mountain Home Junction to Lucky Peak 138 kV line without the Evander Andrews 230/138 kV transfonner. SWNFlPO ,1.01 '" SWANFALLOO'" 9,OMW:r:104M",~) 9.0MW104M", Midpoint West = 910 MW Alternative #1- Lockman Butte-Boise Bench #3 230 kV Outage Without the Evander Andrews 230/138 k V Transformer Figure 3 Adding the Evander Andrews 230/138 kV Transfonner to the above outage, produces a 172% loading on the Mountain Home Junction to Lucky Peak 138 kV line. With the Evander Andrews 230/138 kV transformer in-service, only one other N-1 outage produces overloads that exceed 115% loading and are also greater than existing system overloads for the same N-l. That N-1 is loss of the Rattlesnake to Boise Bench #2230 kV line. Without the Evander Andrews 230/138 kV transfonner in-service , four other N-1 outages produces overloads that exceed 115% loading and are also greater than existing system overloads for the same N-l. They are: Rattlesnake - Boise Bench #2230 kV Line outage Midpoint - Rattlesnake #2230 kV line outage Evander Andrews - Strike 138 kV line outage Strike - Bowmont 138 kV line outage Several other N-1 outages result in overloads below 115% that would require curtailments following the outage to get down to loadings that can be sustained continuously. In some cases , lowering the output of the proposed generator helps to lower the overload, but in one case (Lucky Peak - Micron 138 kV line outage), the overload increases as the proposed generators output is lowered. Alternative #1 is an unacceptable alternative, due to two N-1 outages which produce overloads that exceed 115% of continuous ratings. The Network Rating for Alternative #1 is 0 MW. Alternati ve #2 The following one line diagram depicts the system with Alternative #2 added, full output of the generator, and with no outages. Midpoint West = 1083 Alternative #2 - No Outages Figure 4 The addition of the Evander Andrews 230/138 kV transformer improves the performance of Alternative #2 for most N-l outages , but not all. Alternative #2 has one N-l outage that produces an overload that exceeds 115% of continuous rating and is also greater than existing system overloads for the same N-l. The outage is the Rattlesnake to Boise Bench #1 230 kV line. The following one line diagram depicts this outage at 200 MW of output on the proposed unit. Midpoint West = 1028 Alternative #2 - Rattlesnake to Boise Bench #1 Line Outage (g) 200MW of Output Figure 5 The output of the new unit needs to be restricted to approximately 163 MW to limit the overload to 115% on the Mountain Home Junction to Lucky Peak 138 kV line for this N- outage. For this reason, this alternative does not provide adequate performance for a Network Resource Rating of 200 MW. The following one line diagram depicts this condition. Alternative #2 - Rattlesnake to Boise Bench Line Outage (g) 163 MW of Output Figure 6 Curtailments are required for all three N -1 outages of the 230 k V lines from the Mountain Home area into Boise Bench. Loss of the Rattlesnake to Boise Bench #1 or #2 lines require the proposed unit's output to be lowered to approximately 67 MW to reduce overloads to 100% of the continuous rating or a level that the overload is no worse than it is for the existing system with the same N-1 outage. These contingencies and resulting system perfonnance detennines the Network Resource Rating to be 67 MW for Alternative #2. The loss of the Midpoint to Boise Bench #3230 kV line requires a curtailment to lower a 118% overload of the series capacitors on the Midpoint to Rattlesnake #2230 kV line. This alternative does not pennit the overload to be reduced by lowering the output of the proposed unit. Lowering the output of proposed unit will increase the overload on the series capacitors in question. Other generators would have to be curtailed to solve this overload scenario. Alternative #2 is an unacceptable alternative for the proposed unit at 200 MW for Network Resource Interconnection Service, due to the N-1 outage that produces overloads that exceed 115% of continuous ratings. The Network Resource Rating for Alternative #2 is 67 MW. Alternative #2 is also believed to very similar in cost to Alternative #3 , yet it s perfonnance is much more problematic than Alternative #3. Alternative #3 The following one line diagram depicts the system with Alternative #3 added, full output of the generator, and with no outages. Mld olnt West = 1103 ~... ., ~) It ."':'-.~' I( MI ':;': "9 ' . "m... . , ' ;~"1 V MI"""" 'Y""MICRON ",\ """""'. ". I! "'"'" '" _en """ """"'" ~ii .f!i". "" rP ' ... ( ~2"TMTcr (I', "'\'rir;;:11 Wit """ UD... ~ \1:"::C'::: "'" ,'" ~;:B' ."" ':iit" ,;:;; ~.J ) "1m'. .~""'" U" '-..; 7t-- g~ l!~I.-;~~~;;' "'" "'.i:'. (:;::" 6'1 ;; "'"" ,. . 'tJF,..~"' oj "',",. ,=/'(:.:\ ""' t::' -... "'~ ..;"" t::' I""'" M""" '";?~L\ :' ~ '.,. ,. m... " ' '... '99... ON",,"-1i-, :l1--(~) 5T~" , . "'i"'"", 'I'~....tP,.... .. tP 1\1:'. Alternative #3 - No Outages Figure 7 The addition of the Evander Andrews 230/138 kV transfonner improves the perfonnance of Alternati ve #3 , for all but one of the N -1 outages. Alternative #3 has no N -1 outages that produce overloads that exceed 115% of continuous ratings. Two N-1 outages result in overloads below 115% and at a level that the overload is greater than it is for the existing system with the same N-l outage. The loss of the Midpoint to Boise Bench #3 230 kV line results in a 112% loading on the series capacitor of the Midpoint to Rattlesnake #2230 kV line. This series capacitor is capable of 110% loading continuously, so a 2% reduction in flow is required. Lowering generation in the Mountain Home area results in increased flow on the series capacitor bank, so transfers across the Midpoint West cutplane will need to be reduced to correct this overload, as well as prepare for the next contingency. The second N-1 outage that results in an overload below 115%, is the Evander Andrews to Mora 230 kV line. This N-1 outage results in a 106% loading on the Mountain Home Junction to Lucky Peak 138 kV line. This overload can be managed by opening the Evander Andrews to Mountain Home Junction 138 kV line. Alternative #3 changes the characteristics of the interconnected network enough to create the need to reconductor/rebuild the Evander Andrews to Mountain Home Junction 138 kV line. For the N-1 outage of the Lucky Peak to Micron 138 kV line, the Evander Andrews to Mountain Home Junction 138 kV line loads to 109% of its rating with all the peaking generation in the Mountain Home area at full output. If the output of the peaking generation in 10- the Mountain Home area is reduced, the overload increases in magnitude. The following one line diagram depicts the Lucky Peak to Micron 138 kV line outage with all the Mountain Home area peaking generation offline. Midpoint West = 1157 MW ""'-00' .. un.. If~:: \ '"- " """,me,;-2; ,\/1 0, "'"":'.- . j;~L ,.:,' ~";W"' ~~~ """ t:P l Ii~; "" """""" , .:;J if~'--8-III-"'!'!!ff;1'- ,,1'11\, m", ,..~ '; ..~ ~..;: j:tg!~. ~!~.(;)' ' 'W'" ~:;~. ' ,om;u"" . Alternative #3 - Luck Peak to Micron 138 kV Line Outage With Peakers Off-line Figure 8 Alternative #3 is the recommended alternative for the proposed unit at 200 MW for Network Resource Interconnection Service. Cost Allocation of Proposed Improvements Alternative #3 contains the following five construction components: Bennett Mountain to Evander Andrews 230 kV line and tenninals Evander Andrews to Mora 230 kV line and tenninals 230 kV generator connection tenninal at Evander Andrews Evander Andrews 230/138 kV transfonner and terminals Reconductor/rebuild of the Evander Andrews to Mountain Home Junction 138 kV line A cursory attempt has been made in this study to characterize each transmission improvement as either "needed to integrate the proposed generator" or "needed to correct existing operational concerns . The costs associated with those improvements believed to be "needed to integrate the proposed generator" are allocated to the generator interconnection. The costs associated with those improvements believed to be "needed to correct existing operational concerns " are allocated to IPCo Delivery. 11- Approximate estimated costs allocated to the generator interconnection are: $ 4.1 Million - Bennett Mountain to Evander Andrews 230 kV line and terminals $17.3 Million - Evander Andrews to Mora 230 kV line and terminals $ 0.4 Million - 230 kV generator connection terminal at Evander Andrews $21.8 Million - Total estimated generator interconnection cost Approximate estimated costs allocated to the IPCo Delivery are: $2.1 Million $1.7 Million $3.8 Million - Evander Andrews 230/138 kV transformer and terminals - Evander Andrews to Mountain Home Junction 138 kV line rebuild - Total estimated allocation to IPCo Delivery These cost estimates include direct equipment and installation labor costs, indirect labor costs and overheads , and allowance for funds used during construction (AFUDC). The proposed cost allocation is subject to change, as more information is known. These are cost estimates only and final charges to the customer will be based on the actual construction costs incurred. 10.Short Circuit Study Results Preliminary short circuit study results indicate the surrounding circuit breakers are believed to be able to accommodate the increased fault duty. No circuit breaker replacements are anticipated at this time. 11.Conclusions The feasibility of interconnecting a 200 MW simple cycle gas turbine at Evander Andrews Power Complex to Idaho Power s 230 kV transmission system was studied. Three interconnection alternatives were evaluated. Both Alternatives #1 & #2 were found to be unacceptable alternatives due to transmission system loadings that exceeded 115% for N-l outages. Alternative #3 was found to be an acceptable interconnection alternative. While Alternative #3 does require minimal redispatch/transmission switching for two N-l outages, they are minor in nature and deemed acceptable for this feasibility study. The estimated total cost of the transmission improvements associated with Alternative #3 is approximately $26 Million. At this time it is believed that approximately $22 Million of these estimated costs should be allocated to the generator interconnection. 12- APPENDIX A 1.0 Method of Study The study methodology inserts the proposed generator up to the maximum requested output of 200 MW into the selected WECC power flow case and then, using the PowerWorId Simulator powerflow program, examines the impacts of the new resource on Idaho Power s transmission system (lines , transformers, etc.) within the study area under various operating/outage scenarios. The WECC and Idaho Power reliability criteria and Idaho Power operating procedures were used to determine the acceptability of the alternatives considered. The WECC case is a recent cases modified to simulate stressed but reasonable pre-contingency energy transfers utilizing the IPC system. Acceptability Criteria The following acceptability criteria were used in the power flow analysis to determine the acceptability of the alternatives: Loadings on transmission lines and transformers should not exceed 115% of the continuous rating, immediately flowing any N-1 outage. Loading on the Midpoint 230 kV series capacitors should not exceed 135% of the continuous rating, immediately flowing any N-1 outage. These loadings levels of 115% on transmission lines and transformers and 135% on Midpoint series capacitors correspond to IPCo s 30 minute emergency equipment ratings. Any loadings immediately following an N-1 outage less than the 30 minute emergency rating is acceptable. Loadings which are less than the 30 minute emergency equipment ratings, but greater than the equipment continuous ratings , must be reduced to the continuous ratings by generation curtailments, re-dispatch, or some other operating procedure. Any remedial action schemes(RAS) or other transmission switching, must be judged to be reasonable before the alternatives performance can be deemed acceptable. The continuous rating of equipment is assumed to be the normal thermal rating of the equipment. This rating will be as determined by the manufacturer of the equipment or as determined by Idaho Power. Less than or equal to 100% of continuous rating for transmission lines and transformers is acceptable. Less than or equal to 110% of continuous rating for the Midpoint 230 kV series capacitors is acceptable. Transmission voltages, under normal operating conditions, are maintained within plus or minus 5% (0.05 per unit) of nominal. Therefore , voltages greater than or equal to 95 pu voltage and less than or equal to 1.05 pu voltage are acceptable. The stable operation of the transmission system requires an adequate supply of volt- amperes reactive (V ARs) to maintain a stable voltage profile under both steady-state and dynamic system conditions. An inadequate supply of V ARs will result in voltage 13- decay or even collapse under the worst conditions. Idaho Power designs its system to integrate Network Resources at full capability during specified outage conditions. Equipment/line/path ratings used will be those that are in use at the time of the study or that are represented by IPC upgrade projects that are either currently under construction or whose budgets have been approved for construction in the near future. All other potential future ratings are outside the scope of this study. Future transmission changes may, however, affect current facility ratings used in the study. 14- APPENDIX B 1.0 N -1 Outages That Produce Overloads On The Existing System The following one line diagrams depict system perfonnance following the seven N-l outages that produce overloads which exceed the continuous rating of facilities. Figure 1 on page 5 depicts the operation of the existing system with no outages. The combination of heavy hydro and peaker generation in the Mountain Home area, and 1100 MW east to west transfers on Midpoint West, results in the Mountain Home Junction to Lucky Peak and Lucky Peak to Micron 138 kV lines being loaded to 98% & 99% respectively, prior to any outages. 80""'",m,. Midpoint West = 981 ~~" 'fffF',.,"""'" ~~~'" ,. "...,~1-4:: ,.~i). ""~'.' \""""'" ' 50"""" 0.99,. """'""" """ fa.-"~ "'" ,"'" ~:rr-;D~U/"t""~L 9...,c;';)"". c;';)1~. """"N c;::J,~"" (11, ;8 ~~;;: .;,';~: "tH:'!/toYrtf'" C:J .". m" """"N ";;;.'""'" ."'" Existing System - Midpoint to Boise Bench #3 230 kV Outage Figure 9 15- Mid oint West = 951 I"" """"""'", 9N"""'-C,,\ '" "" ",,'i'--!i1" '---' 'J, :',.","' t8-1 .1./ ..9) 9N"""'- ~'" 'j:01~.~1~. """"N *8 ~':::.,...(?g~ """'11 li~fi \;J ,-r&;'? /;~')"""\; ,~~ (?:J"f~ '~'E~f::~, Ii" 'J"'"W"'" Existing System - Rattlesnake to Boise Bench #2 230 kV Outage Figure 10 Midpoint West = 997 """""",,, "f" f"" tfJ f"" tfJ ::~5 """"'" D, ,.. 9N"""'- """ ia-. """" '1' ~:; ~.;,)\ , 9N"""," ~'" ~~1~.~1~. """"" c;::J:~ ::., ,) c. ~'\~ ,',:':"./ :,.\~. t~'!f! 7-" \'::) "fM',::' ;0 i:' ::;;'"'"' """ Existing System - Midpoint to Rattlesnake #2230 kV Outage Figure 11 16- ~~' , w= " 1:I;'I tP ""'"""" .;, ",),"" ((' , ,...,..... '-""" """""- "1i' ;t';,~ "" '" . '""'" ';:;:;'i ~.i~: J..~~:l-~"" 'j:(gm:~1W. Existing System - Midpoint to DRAM #1230 kV Outage Figure 12 ;L. OlntWest = 1085 MW .;..; C:? g~--4/W" i ..; ?," i "" . ...;.,""""" \:;' . .:~. "'ON; ""'" Existing System - CJ Strike to Bowmont 138 kV Outage Figure 13 17- Midpoint West 1072 MW """...""" ~~ ~3 ~'" ~..;: ~~H1~'~1WN Existing System - Lucky Peak to Micron 138 k V Outage Figure 14 Mid oint West = 1094 MW ,;, "tlf':, IOC"""f~~~ """ """~.I-" -(''"" """"" ""'" SWAN'AU. 1i-~~:: :,"~:~ "'W..sw""" ~,,;: ~!WN~!WN ;~J ""-0011""' """"" iM.'" 101",'0" ,\\;:;;~JL~M," Tmcr .. ,?, ~J'# T(I~F01'f,WN :):';"""";" """UN ~ ";"" ,"" ~.~,::;, 3.~':::;:' '" . 2? 8~ 11Iff! -!,./\':'(""" "IM'~ ~:~:;~...J I:::) ~~..., ",'XU ""N ,,:'""'" c;J ~~ BUR"" ""'" """ '" c;J ~~ MICro"" """ Existing System - Evander Andrews to CJ Strike 138 kV Outage Figure 15 18- ID AH POWER CO MP ANY CASE NO. IPC-O6- FIRST PRODUCTION REQUEST OF COMMISSION STAFF RESPONSE TO REQUEST NO. 28 See documents attached to Response to Request No. 28